Materials Literature
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A monodisperse polystyrene (PS) film was spin-coated on a silicon wafer with native oxide layer and was in part scratched by a blade. Then, the surface modulus on a given area, in which PS and bared silicon were present, was two-dimensionally mapped as a function of temperature by scanning viscoelasticity microscopy.…
This work documents a sharp adsorption cutoff for a cationic polymer (poly(dimethylamino ethyl methacrylate)) adsorbing onto a negative surface (silica) from buffered aqueous solution, as a function of ionic strength. In this system, electrostatic attractions drive adsorption, without contribution from chemical or hyd…
Potassium hydrogen phthalate crystal is a good nonlinear optical system. Its electro-optic coefficient r 131 is measured for a wavelength of 670 nm and it is found to be of the order of that of urea crystal (1.06 pm V −1 ). The dispersion study for the effective Pockels coefficients r eff = r 113 − r 112 , is carried…
Novel mesostructured titanosilicates designated as MTS-9 have been successfully synthesized from assembly of preformed nanosized titanosilicate precursors with polymer surfactants. Mesoporous MTS-9 shows highly hydrothermal stability in boiling water (over 120 h) as compared with that of Ti−MCM-41 and SBA-15. In pheno…
The development of strategies to measure the properties of materials with nanoscopic dimensions is a necessary but challenging topic in nanoscale science and technology. Here, combinatorial arrays of specially designed test structures are used to quantify the deformation of micro‐ and nanoscale polymer beams in respon…
We report on quantum chemical calculations at the DFT (BP86/TZP) and ab initio (CCSD(T)/III+) levels of the title compounds. The geometries, vibrational spectra, heats of formation, and homolytic and heterolytic bond dissociation energies are given. The calculated bond length of Cu-CN is in reasonable agreement with e…
The mineralization of carbon from sewage sludge was studied in a pot experiment during an aerobic incubation with three representative soils of the Pampean Region of Argentina. Surface horizons (0–15 cm) from a Typic Hapludoll, a Typic Natraquoll and a Typic Argiudoll were used. Samples were collected a year after slu…
Abstract A numerical simulation of reaction injection molding (RIM) of polymeric foam is developed, using a finite volume method (FVM). In this study we predict mold filling with a variable‐density fluid that fills a mold by self‐expansion. We deal with two‐dimensional, isothermal cases. With the assumptions of ideal…
Molecular materials containing tungsten polyoxometalates as the active elements embedded into polymer matrices are investigated as candidates for electronic device applications. The transport properties of these materials are investigated varying the interelectrode spacing and the polyoxometalate concentration. The I–…
The crystallization of fluoro-silicate glasses obtained using high-purity SiO2, AlO1.5, CdF2, PbF2, ZnF2, and ErF3 has been investigated. Upon heat treatment, PbF2 nanocrystals form which host most of the Er3+ ions. The major peaks obtained by x-ray diffraction suggest that the nanocrystals are fluorite structured, bu…
We use a fast Fourier transform block Lanczos diagonalization algorithm to study the electronic states of excess electrons in fluid alkanes (methane, ethane, and propane) and in a molecular model of amorphous polyethylene (PE) relevant to studies of space charge in insulating polymers. We obtain a new pseudopotential…
The dynamics of phase separation of binary fluids in the presence of quenched or mobile filler particles, with preferential attraction for one of the two fluid components, is investigated by means of extensive molecular dynamics simulations in two dimensions. When the filler particles are quenched, we found that they…
Nanowires of diblock copolymer have been prepared from separated columnar phases of a polymeric complex. Cylindrical structures are formed and oriented by oscillatory shear forces, from which nanowires several micrometers long and 30–35 nm in diameter can be extracted. These nanowires can be used as templates for both…
We report the growth of the half-Heusler alloy NiMnSb on InP (001) by molecular-beam epitaxy using a lattice-matched (In,Ga)As buffer. High-resolution x-ray diffraction confirms a high crystalline quality. Spot-profile analysis low-energy electron diffraction measurements show well-defined surface reconstructions. The…
Multiwall carbon nanotubes were studied by dc magnetization and electron spin resonance (ESR) measurements. Hole doping is inferred from both the high-field dc susceptibility and ESR parameters complying favorably with the band model of two-dimensional graphite. Paramagnetic deviations are evinced on the diamagnetic s…
Ab initio absorption spectra and optical gaps for CdnSen (n=17,26,38) quantum dots are calculated using time-dependent density functional theory within the local density approximation. The spectra computed using the time-dependent local density approximation technique differ from the ones calculated using conventional…
Three divalent transition metal complexes of 4,5-bis(2-pyridylmethylsulfanyl)-4',5'-ethylenedithiotetrathiafulvalene have been prepared and crystallographically characterized. The isostructural Co(II) and the Ni(II) complexes show octahedral geometries around the metal ions with the coordination sites occupied by the…
Using recently published experimental data we calculated the piezoelectric response of rhombohedral 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 monodomain single crystals along arbitrary directions. The calculations indicate that the value of the longitudinal piezoelectric coefficient along the [001] axis of the pseudocubic syste…
The adsorption of poly(vinyl alcohol) onto hydrophobic surfaces is described. Three different commercial polymer film samples, poly(tetrafluoroethylene- co -hexafluoropropylene)(FEP), poly(ethylene terephthalate) (PET), and poly(4-methyl-1-pentene) (PMP), four different silicon-supported covalently attached monolayers…
Electronically coupled porphyrin arrays are suitable for artificial light harvesting antenna in light of a large absorption cross-section and fast excitation energy transfer (EET). Along this line, an artificial energy transfer model system has been synthesized, comprising of an energy donating meso-meso linked Zn(II)…